TRIO Best Practice articles are brief, structured reviews designed to provide the busy clinician with a handy outline and reference for day-to-day clinical decision making. The ENTtoday summaries below include the Background and Best Practice sections of the original article. To view the complete Laryngoscope article, visit Laryngoscope.
Explore This IssueNovember 2021
The prevalence of clinically palpable thyroid nodules in the general public is estimated at between 4% and 7% (Diagn Cytopathol. 2020;48:1254-1264; JAMA Oncol. 2019;5:204-212; J Natl Compr Canc Netw. 2018;16:1429-1440). Ultrasound can identify additional nodules in up to one third of the population (JAMA Oncol. 2019;5:204-212; J Natl Compr Canc Netw. 2018;16:1429-1440). Despite their high incidence, thyroid nodules most often harbor benign or indolent pathology and frequently require no surgical treatment (Diagn Cytopathol. 2020;48:1254-1264; JAMA Oncol. 2019;5:204-212; J Natl Compr Canc Netw. 2018;16:1429-1440; Thyroid. 2015;25:760-768; Cancer Cytopathol. 2020;128:452-459).
A growing body of information continues to guide one’s workup of thyroid nodularity, with sonographic and histologic findings often spearheading management strategies. For example, the Thyroid Imaging Reporting and Data System, used in conjunction with The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC), can identify a majority of nodules as either benign or malignant. Unfortunately, up to 30% of fine-needle aspirate (FNA) samples can return an indeterminant diagnosis—“Atypia of Undetermined Significance/Follicular Lesion of Undetermined Significance” (AUS/FLUS/Bethesda III) or “Follicular Neoplasm/Suspicious for Follicular Neoplasm” (FN/SFN/Bethesda IV). In this scenario, one’s options are fourfold: observation, repeat FNA, diagnostic surgical excision, or offer molecular testing.
Molecular testing is an increasingly utilized adjunct when evaluating indeterminant thyroid nodules in an effort to avoid unnecessary surgical or diagnostic risk to a patient (Diagn Cytopathol. 2020;48:1254-1264; JAMA Oncol. 2019;5:204-212; J Natl Compr Canc Netw. 2018;16:1429-1440; Thyroid. 2015;25:760-768; Cancer Cytopathol. 2020;128:452-459). Its use is supported by the American Thyroid Association and the National Comprehensive Cancer Network, among other medical societies (J Natl Compr Canc Netw. 2018;16:1429-1440; Thyroid. 2015;25:760-768). The potential utility of molecular evaluation of thyroid nodules is broad, with a possible future role in staging, treatment, disease monitoring, and identifying familial risk among other uses (J Natl Compr Canc Netw. 2018;16:1429-1440; Thyroid. 2015;25:760-768; Cancer Cytopathol. 2020;128:452-459). This review seeks to evaluate the existing literature to determine the utility and applicability of molecular testing in indeterminate thyroid nodules.
Molecular testing can enhance knowledge of the malignant potential of AUS/FLUS/Bethesda III and FN/SFN/Bethesda IV (cytologically indeterminant) thyroid nodules. In addition to helping the patient avoid unnecessary diagnostic surgery, these assessments may provide critical insight as well as offer contemporary personalized treatment options for advanced disease. Molecular testing has no clear role in the management of benign or low-grade/stage malignant lesions. The information attained from these assessments encourages further study into the clinical and genetic characteristics of thyroid malignancy and may help to guide personalized medical care in the future.